The present invention relates to an image input apparatus of high resolution having a transparent member disposed between a solid state imaging device and a picture-taking optical system, wherein the transparent member is capable of being angularly displaced. More particularly, the present invention relates to an image input apparatus in which a tilting device for angularly displacing the transparent member is improved.
Concerning the image input apparatus in which the two-dimensional type imaging device is used, the following method is publicly known:
A relative position between the image and the imaging device is minutely changed. Each time the relative position is changed, the image is inputted. Therefore, the number of pixels is increased in appearance, so that the resolution of the image can be enhanced.
In order to enhance the resolution by the above method, the following techniques are disclosed:
According to Japanese Patent Publication Open to Public Inspection No. 75679/1986, a flat plate of glass is arranged in front of the imaging cell. This flat glass plate is tilted by the vibration generated when a vibration member is driven. In this way, a relative movement is caused between the imaging cell and the image. Further, according to Japanese Patent Publication Open to Public Inspection No. 231589/1991, a parallel flat glass plate is arranged between the imaging device and the photographic lens. The parallel flat glass plate is rotated around the rotational axes of X and Y by a drive mechanism, so that the flat glass plate is minutely tilted and the image passing through the parallel flat glass plate is moved in the directions of X and Y axes with respect to the imaging device.
However, the invention disclosed in Japanese Patent Publication Open to Public Inspection No. 75679/1986 is disadvantageous in the following manner:
A flat plate member (glass) is tilted by a vibration member arranged at one position. Accordingly, in order to shift the pixels two-dimensionally in the direction of X-axis (horizontally) and the direction of Y-axis (vertically), two flat plate members are required, that is, two glass plates are required, one is tilted in the X-axis direction, and the other is tilted in the Y-axis direction. However, when the two glass plates are used, an amount of light is reduced when light passes through the two glass plates, and further the wave-front-aberration is increased and the dimensions of the entire apparatus are extended.
Also, the invention disclosed in Japanese Patent Publication Open to Public Inspection No. 231589/1991 is disadvantageous in the following manner:
According to the invention, one flat glass plate is tilted around both axes of X and Y. In this case, a rotating device for rotating the flat glass plate around the X-axis must be moved when the flat glass plate is rotated around the Y-axis. Therefore, the rotating device for rotating the flat glass plate requires a high drive force, so that the dimensions of the apparatus are extended and the cost is raised.